This invention is generally concerned with document aligning apparatus, and more particularly with apparatus for aligning documents of varying thickness.
This application is related to U.S. Pat. Application Ser. No. 07/599,192 for Document Feeding Apparatus filed concurrently herewith.
As shown in U.S. Pat. No. 4,314,644 for a Zip Code Registration System, issued Feb. 9, 1982 to Stocker, a series of movable balls, located at successive downstream intervals in the path of travel of successive documents being fed to a transversely moving conveyor, have been selectively raised or lowered relative to the conveyor in response to sensing different zip codes marked on the documents, for selectively engaging the leading edges of the successive documents at different positions in the path of travel, to register such leading edges along different lines extending in the direction of movement of the transversely moving conveyor.
As shown in U.S. Pat. No. 4,631,681, for a Microprocessor Controlled D.C. Motor And Application Therefor, issued Dec. 23, 1986 to Salazar et al, a microprocessor controlled d.c. motor, programmed for comparing the actual linear displacement of the periphery of a printing drum with a desired displacement of a sheet being fed thereto during successive sampling time periods, has been utilized in a closed-loop, feedback control system for causing the drum's peripheral displacement to match the sheet's displacement during each sampling time period.
Thus it is generally known in the art to provide document aligning apparatus including movable structure for registering the edges of successive documents, fed in a path of travel, along lines located at different intervals in the path of travel. And it is known in the art to utilize a closed-loop feedback control systems for causing the peripheral speed of a printing drum to match the speed of a sheet fed thereto. Accordingly:
An object of the invention is to provide improved document aligning apparatus including movable document edge registration structure;
Another object is to provide improved apparatus for aligning an edge of a document moving in a path of travel along a predetermined line extending transverse to the path of travel; and
Another object is to provide a closed-loop feedback control system for controlling movement of document edge registration structure.